In general, wireless communication is insecure and vulnerable to attacks. Various techniques may be employed to secure a wireless communication link or to make it less vulnerable to attacks. For example, it is recommended to place a wireless access point away from external walls and to lower the transmit power of its antenna so that the signal strength is strong enough for use inside the building but weak outside of the building where it may be accessible by others.
Bluetooth® wireless technology provides short-range and low power wireless connectivity to eliminate the need for cables to connect computerized devices and their peripheral devices. A non-exhaustive list of examples of computerized devices includes personal computers (PCs), mobile phones, personal digital assistants (PDA), portable computers, pagers, handheld devices, and the like. A non-exhaustive list of examples of peripheral devices includes headsets, printers, keyboards, mice, and the like.
The Bluetooth® specifications were designed with various concepts in mind, including output power control that optimizes power according to device distance. According to the Bluetooth® specification version 1.2, there are three classes of transmitters, and power control is mandatory only for those transmitters in the class where the maximum output power is 100 mW (20 dBm) and the minimum output power at the maximum power setting is 1 mW. At page 33 of the Radio Specification section of the Bluetooth® specification version 1.2, it is stated “The power control (of a power class 1 device) is used for limiting the transmitted power over +4 dBm. Power control capability under +4 dBm is optional and could be used for optimizing the power consumption and overall interference level”.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity.